Public exposure to mobile signals are lower in areas that have a higher density of network antennas, a study of 11.5 million base station signal measurements throughout Colombia has found.
The Colombian National Spectrum Agency (ANE) analysed a year of radio frequency electromagnetic field (RF EMF) measurements in the cities of Bogota, Medellin, Cali and Ibague to check mobile carrier’s equipment met the national safety standards.
“It was found in cities like Medellín, with increased deployment of telecommunications infrastructure, levels of measured electromagnetic fields are lower compared to cities which have less infrastructure deployment, such as the case of Bogota and Cali,” the Colombian Ministry of Information and Communication Technology (MinTIC) reported.
The study found for 2013 the average level of RF EMF from mobile networks was 1.8 per cent of the standard – 55 times lower than the Colombian safety limit.
Measurements were made on broadcasting stations, cellular mobile telephone and other telecommunications services in all regions of the country.
Director of the ANE Oscar Giovanni León Suárez said the results demonstrate that the more network antennas there are in an area the lower the intensity of electromagnetic fields.
“This is due to the fact that the equipment’s power use must diminish when there is more infrastructure,” Suarez said.
GSMA Senior Director of Research and Sustainability Dr Jack Rowley agreed and said the results highlighted a common misconception that the closer phone towers are to users, the higher exposure levels will be.
“Mobile base stations are designed to operate at the lowest power levels required to make quality connections depending on the number of calls they are handling, the surrounding environment and how far away connected devices are from them. Too much power would interfere with nearby cells and limit the system capacity,” Dr Rowley said.
“Mobile phone handsets also constantly adapt to the minimum power required to maintain a quality call, in order to avoid network interference and improve battery life.”
“Optimal design of mobile networks means that exposure to mobile signals is often lower in areas with a high density of network antennas, because both base stations and handsets require less power to connect.”
“That’s why in most cases the best location to install a base station in order to minimise exposure is closest to where the services are required.”
The Columbian safety limits are based on the international guidelines developed by the International Commission on Non-ionising Radiation Protection (ICNIRP), which are recommended by the World Health Organization (WHO).
In 2013 the ANE launched a 24/7 mobile network monitoring system that provides live RF EMF readings from 43 sensors installed across the country’s most populated city areas, which relay exposure level readings back to the website in real-time via an interactive online map.